21/22 - Appetite Flashcards
regulatory system must integrate input from 3?
food, environment, endocrine system
4 correlates of obesity
diabetes type II, cardiovascular issues, stroke, cancer
2 genetic disorders related to obesity
leptin + leptin receptor mutations. melanocortin 4 receptor mutations
set point hypothesis?
body weight very stable in adults; overfed/starved animals will return to normal when fed ad lib
energy stored in form of? signals?
fat: if generated signal proportional to amount, would feedback on content
genetically obese mice: names?
ob/ob mouse = obese. db/db mouse = diabetic. hyperinsulinemic, eat excessively, low energy expenditure. essentially a starvation response.
parabiotic animals: what?
join circulatory systems of 2 animals: share blood + blood borne factors
parabiotic animals: results?
ob + normal: ob loses weight. db + normal: normal loses weight. ob + db: ob loses weight, db no change. overall: ob loses weight when paired with others, db causes others to lose weight
parabiotic animals: results mean? ob vs. db?
there is a circulating factor reporting amount of fat. ob missing this factor, db making excess but can’t sense it
“ob” protein name? made by? ob and db mice?
leptin: made by adipose cells. ob mouse = mutant leptin. db mouse = mutant receptor
leptin concentration proportional to? injection causes?
adioposity. weight loss in normal and ob animals (leptin deficit), but not db animals (receptor problem)
insulin: release from? role? cocentration proportional to?
pancreated B cells; regulates blood glucose levels. proportional to adiposity.
insulin: transport into brain? receptors?
transported into brain in a saturable fashion, located in same areas as leptin receptors (hypothalamus)
action? regulation of secretion?
reduces food intake + body weight when given centrally. secretion actively regulated by meals, unlike leptin.
leptin receptor: what family? defective in who?
cytokine receptor family. defective in db/db mouse
target site of leptin receptors? affects what?
arcuate nucleus: affects synaptic inputs + post synaptic cell properties. reduces NPY/AGRP expression, increases POMC/CART expression
6 central signallers of energy balance
NPY, a-MSH, AGRP, CART, MCH (melanin concentrating hormone), orexin
NPY: expression changes when? injection causes?
expression elevated with restricted food intake. injection into hypothalamus = eating even in satiated animals, doesn’t desensitize
NPY: selective? signal via? energy?
carbs preferred. anabolic signal via reduced symp outflow to reduce brown fat activity and to increase lipogenesis = decreased overall energy expenditure
a-MSH: derivative from? injection causes?
POMC derivative. central injection of melanocortin agonists reduce food intake
